Speedometer Error

[wilinfla]

Has anyone checked what the error for their speedometer is on a Bandit 1250 with their GPS? They put up one of those radar signs to show your spped on my way to work. The last couple of nights I have noticed when I pass it (I am the only vehicle) that when I am indicating 71 MPH it shows my speed at 64 MPH. That seems like a lot, I was just wondering if that is normal. I'm sure the radar sign has some error as well though. It may also explain my lack of speeding tickets too though!


                                                                      Will

[bngboyd]

yeah man that is pretty normal.

7% to 12% optimistic. They do make speedo-healers that can bring it back in but not cheap. I have heard of others who put a 40T sprocket on the back and that helps bring the speedo back in as well. I am not sure why but all the imports seem to be like this. You would think they would sell these bikes with the speedos in spec. 

Bob

[wilinfla]

Thanks, yes you would think they would be a little closer than that. It's just good to know how far off it is, I can live with it. I was wondering why the FHP never gave me a second look as I went by their radar at 20 MPH over the posted limit.

                                                             Will

[Red01]

Sounds pretty traditional.  The 1200's with electronic speedo drives have this kind of error, too.  Seems to be engineered that way.  Most of them even get more optimistic the faster you go... ie; 7% at 35, 10% at 70, 12% at 100...

Check your odometer and I think you'll find it is way more accurate than the speedo... like ~1% or less... so if you correct the speedo with a Speed Healer or Yellow Box or a gearing change, the odo will loose it's accuracy. 

[banditone1250s]

 
  I find that mine is off 10 M.P.H. at 152...When it says 152 I am actually doing 142 according to a friend of mine that I ride with. He has gotten his tuned back in correct and his speedo said 142 M.P.H.  When I go through one of those things that shows you your speed, showing 45 M.P.H. I was showing around 48 M.P.H., so with that being said, I do think that the percentage goes up as your speed goes up...banditone1250s....

  There is a thin line between fear and respect....Feel free to drift across it every now and then...

[txbanditrydr]

...the faster you go... ie; 7% at 35, 10% at 70, 12% at 100...

Checked mine with a GPS last weekend.... you were dead on about the 10% @ 70..... the speedo read 77.

[MattDaddy]

I'm seeing similar GPS to spedo differences at highway speeds.  I was very much wanting to get the spedo recallibrated, assuming that the odometer would also be over by that %.  Red, I hadn't even considered that the spedo and the odometer wouldn't be in lockstep, but I guess if it is all electronic there is no reason they couldn't engineer it to be accurate on one, and overoptimistic on that other. 
 

[dhcolesj]

Hmmmm . . . Has anyone actually checked the Odo?  According to Holeshot's website their speedo healer will also *correct* the Odo.  I'm wondering if anyone has found any evidence of Red01's question about the odo being accurate.  I also wonder, has anyone asked Dale Walker about the Odometer issue and a speedo healer?

Might be a quiz he'd want to investigate.

[SteelD]

Hmmmm . . . Has anyone actually checked the Odo? 

Do you mean the tachometer as opposed to the odometer? The odometer just reads out the total miles travelled. Or are you suggesting that the odometer displays more miles than actually travelled thus depressing the bikes resale value artificially?

[SteelD]

...the faster you go... ie; 7% at 35, 10% at 70, 12% at 100...

Checked mine with a GPS last weekend.... you were dead on about the 10% @ 70..... the speedo read 77.

What makes you think that a GPS has absolute accuracy with which you can assess your speedo?

[dhcolesj]

Hmmmm . . . Has anyone actually checked the Odo? 

Do you mean the tachometer as opposed to the odometer? The odometer just reads out the total miles travelled. Or are you suggesting that the odometer displays more miles than actually travelled thus depressing the bikes resale value artificially?

"I'm" not suggesting anything, I know the speedo is off, as I've also checked with my wife's car (which matched the GPS) and with my GPS.  My question is, "is the Odometer off as well?" which would make sens if the speedo is off.
What I'm questioning is the suggestion that the Odometer is accurate, as I don't think it is.

[Red01]

I've checked my odo against the mile markers on the freeway, both the regular ones and the "speedometer check" ones.  My odo is within 1% accuracy.  It is obviously WAY more accurate than the speedo - which has been checked against portable radar trailers - and once by the State Patrol in an airplane. 

[dhcolesj]

So, what that means is that if you "fix" the Speedo, like by bumping up your back sprocket by 3 teeth, you break the Odometer, unless you can separate out the signals.  I'm wondering if the Speedo Healers on the market leave the Odometer alone.

Also, how did you get that nice officer to clock you from an airplane to calibrate your speedo? 

[Red01]

He was nice enough to clock three of us at the same time! The other two got off with warnings cuz he could only clock three at a time... 

The plus side, was the "certification" was thrown out of court... cost plenty for the lawyer though.

[pmackie]

My 2nd Gen B6 is out a full 11-12% on the speedo, but only about 2.5% on the odo. It used to be closer to 9% & 1%, but I now run a 1 tooth larger rear sprocket than stock.

The odo is way closer than the speedo, but still recores MORE miles (kms in my case) than the bike actually travels.